Direct-acting compound engine



(No Model) 2 Sheets-Sheet 1."

F. W. JENKINS.

DIRECT ACTING COMPOUND ENGINE. No. 287,289. Patented Oqt. 23, 18,83.

.; v u y (No Model.)

2 Sheets-Sheet 2.

F. W. JENKINS.

DIRECT ACTING COMPOUND ENGINE;

Patented Oct. 23, 1883.

NITED STATES PATENT OFFICE,

FRANK WV. JENKINS, OF BROOKLYN, NEV YORK.

I DIRECT-ACTING COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 287,289, dated October23, 1883. Application filed August 23, 1883. (No model.)

To all whom it may concern:

Be it known that I, FRANK W. JENKINS, a citizen of the. United States,residing in the city of Brooklyn, county of Kings, and State of NewYork, have invented certain new and useful Improvements in Direct-ActingOompound Engines, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.i

This invention relates to direct-acting e11- gincs generally, but moreparticularly to engines of the class shown and described in UnitedStates Letters Patent No. 24,838, and known as the \Vorthington D uplexPumping Engine. In order to secure the successful op eration of thisclass of engines, the two following conditions must be maintained:First, a uniform or nearly uniform propulsive power must be maintainedthroughout the en tire stroke of the engine; and, second, the propulsiveenergy of the steam must be so divided that each side of the engine willdevelop one-half the total power. The first of these conditions isimposed by the fact that no balance-wheel is used, and as the load uponthe engine is uniform, or nearly so, throughout the entire stroke, anyconsiderable falling off in the power applied to the steam -pistonswould result in slowing and finally stopping the engine before it hadreached the end of its stroke. The second condition is imposed by thenecessity of having the pistons or plungers of both of the pumps of thesame size, which is requisite in order to secure a steady and uniformdischarge of water.

'It is well known to those familiar with the science ofsteam-engineering that steam can be most economically used at acomparatively high pressure, and also that in order to utilize thelargest proportion of the power generated it is necessary to use thesteam expansively. In using steam'upon this principle, however, itspropulsive force necessarily decreases toward the end of the stroke, andthis decrease, unless compensated for, results in a spasmodic operationof the engine and destroys the first of the conditions above named. Thisbeing the case, it has been found impracticable, in direct' actingengines, to utilize the expansive energy.

of the steam to any considerable extent, except by the employment ofcompound cylinders, and even by this means the amount of expansionpermissible is comparatively limited.

It is the object of the present invention to produce a direct-actingengine in which the steam can be first used at a high pressure, andexhausted only after its expansive energy has been nearly or quiteexpended, and in which a uniform propulsive power will be maintainedthroughout the entire stroke.

To that end the invention consists, broadly, in a direct-acting enginehaving one or more cylinders which are arranged to receive steam directfrom the boiler and discharge it into a 6 5 tank, a second cylinderarranged to receive- .steam from said tank, and a third cylinderarranged to receive steam from the exhaust of the second. I

The invention also embraces various combi- .70 nations and organizationsin a duplex engine, all of which will be hereinafter fully explained andparticularly pointed out. 4

In the accompanying drawings, Figure 1 is a plan View, partly insection, of a duplex pumping-engine embodying the present invention.Fig, 2 is a transverse vertical section taken upon the line .2 z ofFigs. land 3. Fig. 3 is a side elevation of the same, and Fig. 4 is adiagrammatic section taken upon the line a: x of Figs. 1 and Referringto said figures, it will be seen that the opposite sides of the engineare exact duplicates, each consisting of one high-pressure cylinder, 10,which receives its steam direct from the boiler and discharges itinto atank, one high-pressure cylinder, 11, which receives its steam from saidtank, and one expanding low-pressure cylinder, 12, which receives itssteam from the cylinder 11 and exhausts, it into a condenser, thecylinders 11 12 being arranged to operate upon the well-known compoundprinciple. These cylinders, although here shown as made in one piece andintegral with each other, for convenience of illustration, will ofcourse be constructed and supported in the usual manner. The cylinders10 11 12 are provided with the usual pistons, the rod or rods of whichare connected directly to the load, which in the case shown is 100 theplungers or pistons of the pumps. The pistons of the several cylindersmay be provided with independent rods; but as here shown the pistons ofthe cylinders 11 12 of each side of the engine are attached to a singlerod, 16, while the pistons of j the cylinders are provided withindependent rods 17, which are connected to the rods 16 by crossheads18. The several cylinders are provided with the usual steamchests, 13 1415, the valves of the chests 14 15 upon each side of the engine beingoperated by a single rod, 19, while the valves of the chests 13 areoperated by independent rods 20, which are connected to the rods 19 bycross-heads 21, so that all of the valves of each side of the engine areoperated simultaneously. Each side of the engine is provided with theusual air-pumps, 22, for withdrawing the water and vapor from thecondenser, which are operated from the piston-rods 16 through links 245and double bellcrank levers 23', all arranged in the usual manner. Thevalve-rod 19 of each side of the engine is operated, as is common induplex engines, by the piston-rod of the opposite side through a link 3,rock-arm 4, rock-shaft 5, rock-arm 6, link 7, and rock-arm 8, extendingfrom the shaft 9 of the lever 23, all of which parts are arranged in thecommon and well-understood manner.

The operation of the engine thus organized ,is as follows: The throttle25 being opened, the steam will pass from the boiler through of saidcylinders.

the pipe 26 to the cylinders 10, where it will act upon the pistons ofsaid cylinders at its full pressure throughout the whole stroke. As thepistons in these cylinders commence their return-stroke, the steamalready in the cylinders will pass through the pipes 27 and enter thetank 28 at a reduced pressure. The tank 28, which is thus kept suppliedwith steam, serves as a boiler or reservoir from which the steam issupplied to the cylinders 11. At the same time that the steam isadmitted to the cylinders 10 from the boiler it is admitted from thetank 28 through the pipe 29 to the cylinders 11, in which cylinders itwill act at the full tank-pressure throughout the whole stroke, afterwhich, as the pistons in said-cylinders commence their return-stroke,the steam already in the cylinders will pass through the pipes 30 intothe cylinders 12, where it will act expansively upon the pistons Afterperforming its work in the cylinders 12 and parting with nearly .orquite the whole of its expansive energy, the steam will be exhaustedthrough the pipes 31 into the condenser 32, from which, as beforestated, the water and vapor will be drawn through the pipe 33 by thepumps 22. The connections by which the valves of each side of the engineare operated by the movement of the other side will of course be soadjusted as to properly time the movements of the two sides withrelation to each other. The cylinders 10 are of such size with relationto the cylinders 11 as to maintain the proper pressure in the tank 28.The cylinders 11 12 are of such relative size that the steam acting upontheir pistons, as just described, will exert a nearly or quite uniformpropulsive power throughout the entire length of the stroke, and as thepropulsive power exerted by the cylinders 10 is uniform throughout theentire stroke, it follows that the power exerted by the entire engine isuniform throughout the entire stroke.

By the employment of the hi gh-pressure cylinders 10 the steam can bereceived from the boiler at a comparatively high pressure, so that afterperforming its work in said cylinders. it can be exhausted into the tankat as high a pressure as would be maintained in the boiler if only thecylinders 11 12 were employed, thereby gaining all the advantages due tothe use of the steam at a high initial pressure, and at the same'timethe benefits of as high a ratio of expansion as is permissible withoutdestroying the uniformity of the propulsive power of the engine.

In those engines in which the steam, after being used in one cylinder,is discharged into a tank from which it is drawn into a larger cylinderto be used a second time, it has been found difficult to maintain asuniform a pressure in the tank as is desirable. This lack of uniformityarises from the fact that as soon as the exhaust-valve of thedischarging-cylinder is opened, the entire contents of that cylinderimmediately expands into the tank, thereby raising the pressure more orless, according to the size of the tank, the pressure then beinggradually lowered as the receiving-cylinder is filled. Thisirregularity, which, although not fatal, is very objectionable in adirect-acting engine, is overcome in the present organization byconnecting the cylinders 10 11 of both sides of the engine with the sametank.

It is well known to those familiar with the operation of duplex enginesthat the valves are so operatedthat one side of the engine will commenceits stroke just before the opposite side has completed its stroke in thesame direction, from which it results, in the present organization, thatat the time when the press ure in the tank is being lowered by thewithdrawal of steam to fill the cylinder 11, upon one side of theengine, and just at the point when such reduction in pressure is beingmost felt by the engine, the tank is replenished and its pressurerestored by the discharge of steam from the cylinder 10 of the oppositeside of the engine, thus neutralizing the reduction in pressure causedby the withdrawal of steam and maintaining a practically uniformpressure in the tank.

Although, for the reason just stated, the present invention isespecially applicable to duplex engines, yet it will readily be seenthat it may be applied with advantage to single as well as duplexengines.

The relative sizes of the several cylinders may of course be varied tosuit local conditions and to secure the results specified, theproportions shown in the drawings being only an approximation of theproper proportions, for the purpose of illustrating the principle andoperation of the invention.

In some cases it may be found desirable to,

provide the engine, or each side of the engine, if it be of duplex form,with more than three cylinders, and this can be done, if desired,without departing from or losing the advantages of the invention.

In some cases it may be found desirable to provide the engine, or eachside or the engine, with two or more of the cylinders 10, which shall bearranged to receive steam direct from the boiler and discharge it into-the tank. The cylinder or cylinders 10 will preferably be located atthe side of the cylinder 11, as shown in the present case, as thisarrangement produces a very compact organization and renders the partseasily accessible. They may, however, if desired, be arranged in anyother convenient position. If preferred, all three of the cylinders maybe arranged upon the same axial line, so that their pistons can besecured to a single rod; or all or any two of the cylinders may bearranged in the well-known annular form; or any other convenient ordesirable arrangement may be adopted.

Although it is preferable that both of the cylinders 10 should dischargeinto the same 1. In a direct-acting engine, the combination, with thecylinder 10, arranged to receive steam direct from the boiler anddischarge it'into a tank, of the cylinder 11, arranged to receive steamfrom said tank, and the cylinder 12, arranged to receive steam from theexhaust of the cylinder 11, substantially as described.

2. A duplex engine, each side of which is provided with a cylinder, 10,which receives steam direct from the boiler and discharges it into atank, a cylinder, 11, which receives steam from the tank,'and acylinder,12, which receives steam from the exhaust of the cylinder 11,substantially as described.

A duplex engine, each side of which is provided with a cylinder, 10,which receives steam direct-from the boiler, and discharges it into acommon tank, 28, a cylinder, 11, which receives steam from said tank,and a cylinder, 12, which receives steam from the exhaust of thecylinder 11, substantially as described.

4. A duplex engine, each side of which is provided with a cylinder, 10,which receives steam direct from the boiler and discharges it into atank, a cylinder, 11, which receives steam from the tank, 'a cylinder,12, which re- I ceives steam from the exhaust of the cylinder 11, andconnections by which its inlet and outlet valves are operated by theopposite side of the engine, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

FRANK WV. JENKINS. lVitnesses:

' J. A. HOVEY,

'I. H. PALMER.

